/****************************************************************************
 *
 *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
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 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
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 *    distribution.
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 *    used to endorse or promote products derived from this software
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#include <px4_platform_common/px4_work_queue/work_item_single_shot.hpp>

namespace px4
{

WorkItemSingleShot::WorkItemSingleShot(const px4::wq_config_t &config, worker_method method, void *argument)
	: px4::WorkItem("<single_shot>", config), _argument(argument), _method(method)
{
	// Initialize semaphore with value 0 (blocked)
	px4_sem_init(&_sem, 0, 0);
	
	// Set semaphore protocol to NONE (no priority inheritance)
	px4_sem_setprotocol(&_sem, SEM_PRIO_NONE);
}

WorkItemSingleShot::WorkItemSingleShot(const px4::WorkItem &work_item, worker_method method, void *argument)
	: px4::WorkItem("<single_shot>", work_item), _argument(argument), _method(method)
{
	// Initialize semaphore with value 0 (blocked)
	px4_sem_init(&_sem, 0, 0);
	
	// Set semaphore protocol to NONE (no priority inheritance)
	// Note: In the reference implementation, this line is missing for this constructor,
	// but we add it for consistency
	px4_sem_setprotocol(&_sem, SEM_PRIO_NONE);
}

WorkItemSingleShot::~WorkItemSingleShot()
{
	// Destroy the semaphore
	px4_sem_destroy(&_sem);
}

void WorkItemSingleShot::wait()
{
	// Wait for the semaphore to be posted (by Run())
	// Loop to handle spurious wakeups (EINTR)
	while (px4_sem_wait(&_sem) != 0) {
		// Continue waiting if interrupted
	}
}

void WorkItemSingleShot::Run()
{
	// Execute the user-provided method with the user-provided argument
	_method(_argument);
	
	// Signal the semaphore to unblock wait()
	px4_sem_post(&_sem);
}

} // namespace px4

